Moties are the human name for the alien species which inhabit the Mote system in The Mote in God’s Eye. Their defining factors are their asymmetrical anatomy, their genetically hardwired reproductive rate, and their instinctive specialization, which makes each caste innately expert at the jobs they are bred for.
Physiology
Inhabiting the planet Mote Prime and most of the habitable orbiting bodies in Mote System, as well as many artificial orbiting constructs, the Moties' primary distinguishing physical feature is their specialization into castes. Castes mentioned in the chronicles include Mediators, Engineers, Masters, Warriors, Doctors, Runners, Porters, Farmers, Laborers, and Meats. All of these castes are in the entourage of a Master. Feral forms have also been observed. Engineers use the semi-intelligent Watchmaker caste (called "miniatures" or "brownies" by the crew of MacArthur) as mobile tools. Where a human can to a greater or lesser degree carry out similar tasks, a Motie of a given specialization performs a single function at a high level with no training.
Moties alternate between being male and female. A female Motie will revert to male after giving birth, changing back to female after a time. At some point the female must become pregnant again or else the hormone imbalance will kill her. This life cycle naturally forces Moties to become pregnant whenever possible.
Although the original four-armed symmetrical Motie body plan still exists, the typical member of the species inherits an ancient asymmetrical mutation. Most Moties have two right arms for delicate manipulation and a much heavier and stronger left arm. An equivalent left-handed form with two human-scale left arms and a heavy right arm also exists. The gripping hand has only three large fingers, while the other two smaller hands have six each — four fingers and two opposable thumbs. By analogy with humans counting in base-10, supposedly as a result of having ten digits, the Moties count in base-12 numbers to match the combined digits on their right hands. The strong gripping arm also attaches to one side of the head for greater leverage.
Moties have no spine, instead developing three bones which perform a similar function. During first contact with humans, the Moties found the spine to be of great interest.
Culture
Masters command the loyalty and obedience of groups of other kinds of Moties, such as Engineers, Warriors, Doctors, etc. However they are not good negotiators. Mediators were created as sterile hybrids of the white Masters and brown Engineers to minimize the number of wars between rival Masters. Mediators will always obey Masters, so they cannot themselves change the direction of Motie civilization, but they have considerable latitude to do their job. There is no monetary economy as such, but Masters barter prestige, material goods, etc. A few sterile Masters (unlikely to attempt a takeover for their children) are designated as Keepers and given control of the Museums where knowledge is carefully stored to aid recovery after collapse. When a civilization is doing well, alliances of Masters can cooperate to achieve great things, but the urge to reproduce always causes the alliances to break down, usually resulting in catastrophic wars.
Castes
Motie castes are physically distinct, and differ in coloring, body size and the number and size of the arms. Each of the castes, such as the Masters and Engineers, are so different genetically that they form separate species. While a mating pair composed of two castes may produce offspring together, the offspring are usually sterile, as with the Mediators. Obedience has been bred into the inferior castes, so Engineers will obey Masters and Mediators without question, while Watchmakers take instruction from Engineers. Warriors can only be controlled by Masters, and their Master's Mediators. Even then it takes a certain number of Masters to control an army of Warriors.
From time to time in Motie history attempts have been made to eliminate some of the castes, but these have never succeeded. Some Master has always kept a small breeding stock of the forbidden caste, from which the numbers have been rapidly replenished.
Each of the listed castes come in numerous space-adapted and planet-bred versions, however space and planet castes can interbreed successfully within their caste to produce fertile offspring.
Masters: Motie Masters have white fur and are described as decision makers by the Mediators. Some might be ship commanders; others might be warlords who control large territories. Masters have the biological imperative to breed and protect their offspring and siblings; however, sterile individuals, or those who have bred a sufficient number of times, can hold positions for the good of the Race. These positions include that of Keeper. Keepers are responsible for the safeguard of the "museums" that preserve technology so that the survivors of a Collapse can find the tools to rebuild civilization as quickly as possible.
Engineers: Motie Engineers (also referred to as Browns) have brown fur and are essentially idiot savants. They communicate very little but are geniuses when it comes to anything mechanical or electrical. They can build, modify, or repair almost anything with great speed and competency. Engineers tend to have a supply of Watchmakers on hand, which they regularly cull to keep the numbers down, for instance tossing most out into the vacuum of space, keeping a few back to use and breed.
Watchmakers: Watchmakers are not Moties proper, but a related non-sentient, "animal" subspecies. Genetic tests indicate they are likely a degenerate offshoot of the brown Engineer sub-species. They are about a third the size of Moties, have four arms and brown-and-white mottled fur. They are used by Engineers as assistants and share that caste's ability and ingenuity with anything mechanical or electronic. According to the ambassador Moties at the end of The Mote in God's Eye, "Watchmakers given time to adapt can destroy any ship. They contribute greatly to a collapse. If they were not so useful we would have them exterminated."
Mediators: Mediators are created by breeding Master moties with Engineers. They have mixed white/brown fur and are highly empathetic. They are sterile mules, and because of this their lifespan is shorter than average—about 25 years. Since Moties sexually mature in 10 years the useful life of a Mediator is short. Mediators learn languages very quickly, which is essential on Mote Prime with its millions of years of population-explosion cycles and competing Masters. They are actually a product of genetic engineering, with their ability to think independently carefully tuned to allow them to negotiate away conflicts while still being loyal to a Master. Mediators can commandeer any kind of transport, so they can travel quickly to disfuse hostilities. Extremely fast aircraft are reserved for Mediators alone, as Masters will not trust each other to use them for peaceful purposes. In order to represent their Masters in negotiations (with some leeway), Mediators are assigned with the intention that they will learn not only the language but also the culture and personality of their host. Mediators have a word - Fyunch(click) - which describes their relationship with a counterpart whom they must learn about and emulate in every way. Mediators emulate the sound of the voice and the mannerisms of their counterpart.
Warriors: Warriors are controlled by Masters and far surpass any human warriors or soldiers. They can operate and maintain any weapon, fire with deadly accuracy, throw objects at high speed, and fight hand-to-hand using built-in weapons. These include fangs, hard edges and horny points on the limbs and extremities, and a vestigial second left arm adapted as a bone dagger. Warriors have enhanced senses, especially vision, enabling them to resolve detail at a distance impossible for a human. They are described as "standing like coiled springs". Their marksmanship is described as "inhumanly accurate": one of the midshipmen is told by his fyunch(click) that "...if you've exposed an eye, any Warrior could have shot it out."
War Rats: During an earlier cycle of societal collapse, a subpopulation of Warriors also degenerated into a wild miniature form which appears in the first novel as a zoo animal and in the second novel as a War Rat, a spaceborne version with Watchmaker abilities living in hive-like space colonies. It is implied that War Rats and Watchmakers can interbreed forming a hybrid sterile mule variant that is voracious and skilled at building miniature weapons.
Doctors: The last of the truly sentient Motie classes, the Doctors are to physiology what Engineers are to electronics. They have a great store of instinctive physiological knowledge, can manipulate the smallest objects, and can build, or cause to be built, any necessary medical devices. Their fur is a rust-red color. While Doctors do not fight, there is a Doctor-Warrior hybrid that fills the role of the field medic. A doctor-master hybrid was bred to serve as a medic for injured humans.
Runners: Runners are employed carrying messages and are much taller than other Moties, but the Runner is mostly leg. The Gripping Hand also describes a variety of Runner whose multicolored layers of erectile hairs allow it to camouflage itself while delivering messages.
Porters: These semi-sentient Moties do menial jobs, carrying heavy objects. Much taller than the average Moties the Porter has symmetrical strong arms. A feral version of the porter, with large claws on its hands, was seen in the zoo.
Farmers: Farmer Moties tend crops, which grow on whatever land is not covered by buildings or roads. They ignore anything except plants and anything that seems to threaten the plants, being essentially agricultural relatives of the Engineers. Their hands and feet are adapted for digging and tamping down soil. They can operate machinery such as tractors.
Meats: A non-sentient Motie caste bred as a food supply, they were kept in museums and zoos as a relic of an earlier time, and in case they become necessary again in another crisis cycle.
Hybrids: Besides the Mediators, several other hybrid types were mentioned in the books. The doctor and warrior castes were crossed for a field medic. The engineer and warrior became an engineer with combat capabilities. A master and doctor cross was for when more thought was needed in addition to the doctor caste's instinctual medical ability (this was thought to be useful when the Moties needed to treat an injured human.) It is unknown whether these crosses are mules or fertile. The implication is that all crosses are sterile, else they would form a separate breeding caste as the others do.
Technology
After thousands of Cycles, the Motie system has depleted its natural reserves of important materials. When humans arrive in the system, consumables such as fossil fuels and radioactives had long since been exhausted. As the Moties are said to be using all of the easily-accessible metal in the system, making something new invariably involves dismantling something else, rendering metal quite valuable. Where human technology relies on specialized devices, often with multi-redundant backups, Moties rely on the technological idiot savant Engineers, assisted by the semi-intelligent miniature Watchmakers, to constantly build and rebuild devices to order, recycling existing parts that are not needed at the moment. For instance, rather than have a programmable autopilot in a ship, an Engineer would build one to send a ship to a new location, using its ever-present kit of tools and advanced materials. Moties do not use computers as such, relying on the instincts of their specialized castes for jobs such as space navigation. On the ground, Engineers drive at breakneck speed on crowded roads without fear of collision, and upon reaching destination, will dismantle their cars so they won’t take too much parking space.
Another feature of Motie technology is that, to save material and weight, devices perform multiple functions simultaneously, such as being both structural components and sensors. However, having adapted to space, the off-planet Moties are at home in zero gravity and do not have to spin their ships. This has important consequences for the structure of their ships, which are always in flux in any case.
In the first book, one of the complaints of the Motie ambassadors was that they had no Engineer with them to customize their cabin and beds, and to build them devices to help them live more comfortably. This decision was made by their Masters so as to not give away the secrets of Motie biology, especially the reproductive compulsion.
Crazy Eddie
This is a translation of the term the Moties use for any exercise in futility, or any attempt to do, or even think about doing, anything to try to stop the inevitable collapse of their current civilization which is war driven by overpopulation. Their version of the Alderson Drive was called the Crazy Eddie Drive. The spaceship sent to New Caledonia was called the Crazy Eddie Probe, particularly since the effort needed to send it on its way with huge lasers caused a collapse all by itself. The Mediator assigned to Rod Blaine goes Crazy Eddie, infected by Blaine's idealism. Going Crazy Eddie is an occupational hazard for these Mediators, who cannot deal with humans' ability to switch between different roles in their society, or who succumb to the optimism inherent to human nature.